This invention relates to a pharmaceutical composition containing macrolide compound, said composition being stable and having very satisfactory absorption kinetics and/or a low irritation potential. This composition finds application in the therapy and prophylaxis of various diseases of the skin.
The tricyclic compound and its pharmaceutically acceptable salt, which is a representative of the macrolide compound for use in accordance with this invention, is known to have excellent immunosuppressive activity, antimicrobial activity and other pharmacological activities and, as such, be of value for the treatment or prevention of rejection reactions by transplantation of organs or tissues, graft-vs.-host diseases, autoimmune diseases, and infectious diseases [EP-A-0184162, EP-A-0323042, etc.].
Particularly, FK506 Substance among such tricyclic compound (I), which has been shown to be useful for the therapy and prevention of graft rejection in organ transplantation due to its quite excellent immunosuppressive activity.
It is mentioned in EP-A-0315978 that an ethanol solution of FK506 Substance is effective in arresting inflammatory reactions and that FK506 Substance can be provided in the form of a lotion, a gel or a cream. However, there is no specific disclosure of such dosage forms.
Meanwhile, EP-A-0474126 discloses an ointment comprising FK506 substance and its analogs, a dissolution/absorption promoter added in a sufficient amount to dissolve the active compound, and an ointment base.
Further, WO94/28894 discloses a lotion comprising FK506 substance and its analogs, a dissolution/absorption promoter, a liquid base, and, optionally, an emulsifier and/or a thickener.
In the treatment of diseases of the skin, an ointment transitionally constitutes the cardinal regimen. However, a variety of dosage forms are needed, as a matter of fact, in order to cope with different symptoms or lesions in different sites.
The inventors of this invention explored in earnest for a pharmaceutical composition suited for the administration of a macrolide compound, a representative of which is FK506 Substance, and discovered a dosage form having very satisfactory characteristics, namely stability, good percutaneous absorption and/or low skin irritation potential. Thus, the present invention specifically relates to a gel preparation comprising the macrolide compound for external application.
In accordance with this invention there is provided a pharmaceutical composition comprising said macrolide compound, a dissolution/absorption promoter and a pharmaceutical base, and optionally a compatibilizing agent and/or a thickener.
The term xe2x80x9cmacrolide compoundxe2x80x9d for use in accordance with the invention is the generic name of compounds with 12 members or more, which belong to macrocyclic lactones. Abundant macrolide compounds generated by microorganisms of the genus Streptomyces, such as rapamycin, tacrolimus (FK506), and ascomycin, and the analogs and derivatives thereof are included in the term macrolide compound.
As a particular example of the macrolide compound, the tricyclic compound of the following formula (I) can be exemplified. 
(wherein each of adjacent pairs of R1 and R2, R3 and R4 and R5 and R6 independently
(a) is two adjacent hydrogen atoms, but R2 may also be an alkyl group or
(b) may form another bond formed between the carbon atoms to which they are attached;
R7 is a hydrogen atom, a hydroxy group, a protected hydroxy group, or an alkoxy group, or an oxo group together with R1;
R8 and R9 are independently a hydrogen atom or a hydroxy group;
R10 is a hydrogen atom, an alkyl group, an alkyl group substituted by one or more hydroxy groups, an alkenyl group, an alkenyl group substituted by one or more hydroxy groups, or an alkyl group substituted by an oxo group;
X is an oxo group, (a hydrogen atom and a hydroxy group), (a hydrogen atom and a hydrogen atom), or a group represented by the formula xe2x80x94CH2Oxe2x80x94;
Y is an oxo group, (a hydrogen atom and a hydroxy group), (a hydrogen atom and a hydrogen atom), or a group represented by the formula Nxe2x80x94NR11R12 or Nxe2x80x94OR13;
R11 and R12 are independently a hydrogen atom, an alkyl group, an aryl group or a tosyl group;
R13, R14, R15, R16, R17, R18, R19, R22 and R23 are independently a hydrogen atom or an alkyl group;
R24 is an optionally substituted ring system which may contain one or more heteroatoms;
n is an integer of 1 or 2; and
in addition to the above definitions, Y, R10 and R23, together with the carbon atoms to which they are attached, may represent a saturated or unsaturated 5- or 6-membered nitrogen, sulfur and/or oxygen containing heterocyclic ring optionally substituted by one or more groups selected from the group consisting of an alkyl, a hydroxy, an alkoxy, a benzyl, a group of the formula xe2x80x94CH2Se(C6H5), and an alkyl substituted by one or more hydroxy groups.
Preferable R24 may be cyclo (C5-7)alkyl group, and the following ones can be exemplified.
(a) a 3,4-di-oxo-cyclohexyl group;
(b) a 3-R20-4-R21-cyclohexyl group,
xe2x80x83in which
R20 is hydroxy, an alkoxy group, an oxo group, or a xe2x80x94OCH2OCH2CH2OCH3 group, and
R21 is hydroxy, xe2x80x94OCN, an alkoxy group, a heteroaryloxy which may be substituted by suitable substituents, a xe2x80x94OCH2OCH2CH2OCH3 group, a protected hydroxy group, chloro, bromo, iodo, aminooxalyloxy, an azido group, p-tolyloxythiocarbonyloxy, or R25R26CHCOOxe2x80x94,
xe2x80x83in which
R25 is optionally protected hydroxy or protected amino, and
R26 is hydrogen or methyl, or
R20 and R21 together form an oxygen atom in an epoxide ring; or
(c) cyclopentyl group substituted by methoxymethyl, optionally protected hydroxymethyl, acyloxymethyl (in which the acyl moiety optionally contains either a dimethylamino group which may be quaternized, or a carboxy group which may be esterified), one or more amino and/or hydroxy groups which may be protected, or aminooxalyloxymethyl. A preferred example is a 2-formyl-cyclopentyl group.
The definitions used in the above general formula (I) and the specific and preferred examples thereof are now explained and set forth in detail.
The term xe2x80x9clowerxe2x80x9d means, unless otherwise indicated, a group having 1 to 6 carbon atoms.
Preferable examples of the xe2x80x9calkyl groupsxe2x80x9d and an alkyl moiety of the xe2x80x9calkoxy groupxe2x80x9d include a straight or branched chain aliphatic hydrocarbon residue, for example, a lower alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, neopentyl and hexyl.
Preferable examples of the xe2x80x9calkenyl groupsxe2x80x9d include a straight or branched chain aliphatic hydrocarbon residue having one double-bond, for example, a lower alkenyl group such as vinyl, propenyl (e.g., allyl group), butenyl, methylpropenyl, pentenyl and hexenyl.
Preferable examples of the xe2x80x9caryl groupsxe2x80x9d include phenyl, tolyl, xylyl, cumenyl, mesityl and naphthyl.
Preferable protective groups in the xe2x80x9cprotected hydroxy groupsxe2x80x9d and the xe2x80x9cprotected aminoxe2x80x9d are 1-(lower alkylthio)-(lower)alkyl group such as a lower alkylthiomethyl group (e.g., methylthiomethyl, ethylthiomethyl, propylthiomethyl, isopropylthiomethyl, butylthiomethyl, isobutylthiomethyl, hexylthiomethyl, etc.), more preferably C1-C4 alkylthiomethyl group, most preferably methylthiomethyl group;
trisubstituted silyl group such as a tri(lower)alkylsilyl (e.g., trimethylsilyl, triethylsilyl, tributylsilyl, tert-butyldimethylsilyl, tri-tert-butylsilyl, etc.) or lower alkyl-diarylsilyl (e.g., methyldiphenylsilyl, ethyldiphenylsilyl, propyldiphenylsilyl, tert-butyldiphenyl-silyl, etc.), more preferably tri(C1-C4)alkylsilyl group and C1-C4alkyldiphenylsilyl group, most preferably tert-butyldimethylsilyl group and tert-butyldiphenylsilyl group; and an acyl group such as an aliphatic, aromatic acyl group or an aliphatic acyl group substituted by an aromatic group, which are derived from a carboxylic acid, sulfonic acid or carbamic acid.
Examples of the aliphatic acyl groups include a lower alkanoyl group optionally having one or more suitable substituents such as carboxy, e.g., formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, hexanoyl, carboxyacetyl, carboxypropionyl, carboxybutyryl, carboxyhexanoyl, etc.; a cyclo(lower)alkoxy(lower)alkanoyl group optionally having one or more suitable substituents such as lower alkyl, e.g., cyclopropyloxyacetyl, cyclobutyloxypropionyl, cycloheptyloxybutyryl, menthyloxyacetyl, menthyloxypropionyl, menthyloxybutyryl, menthyloxypentanoyl, menthyloxyhexanoyl, etc.; a camphorsulfonyl group; or a lower alkylcarbamoyl group having one or more suitable substituents such as carboxy or protected carboxy, for example, carboxy(lower)alkylcarbamoyl group (e.g., carboxymethylcarbamoyl, carboxyethylcarbamoyl, carboxypropylcarbamoyl, carboxybutylcarbamoyl, carboxypentylcarbamoyl, carboxyhexylcarbamoyl, etc.), tri-(lower)alkylsilyl(lower)alkoxycarbonyl(lower)alkylcarbamoyl group (e.g., trimethylsilylmethoxycarbonylethylcarbamoyl, trimethylsilylethoxycarbonylpropylcarbamoyl, triethylsilylethoxycarbonylpropylcarbamoyl, tert-butyldimethylsilylethoxycarbonylpropylcarbamoyl, tri-methylsilylpropoxycarbonylbutylcarbamoyl, etc.) and so on.
Examples of the aromatic acyl groups include an aroyl group optionally having one or more suitable substituents such as nitro, e.g., benzoyl, toluoyl, xyloyl, naphthoyl, nitrobenzoyl, dinitrobenzoyl, nitronaphthoyl, etc.; and an arenesulfonyl group optionally having one or more suitable substituents such as halogen, e.g., benzenesulfonyl, toluenesulfonyl, xylenesulfonyl, naphthalenesulfonyl, fluorobenzenesulfonyl, chlorobenzenesulfonyl, bromobenzenesulfonyl, iodobenzenesulfonyl, etc.
Examples of the aliphatic acyl groups substituted by an aromatic group include ar(lower)alkanoyl group optionally having one or more suitable substituents such as lower alkoxy or trihalo(lower)alkyl, e.g., phenylacetyl, phenylpropionyl, phenylbutyryl, 2-trifluoromethyl-2-methoxy-2-phenylacetyl, 2-ethyl-2-trifluoromethyl-2-phenylacetyl, 2-trifluoromethyl-2-propoxy-2-phenylacetyl, etc.
More preferable acyl groups among the aforesaid acyl groups are C1-C4 alkanoyl group optionally having carboxy, cyclo(C5-C6)alkoxy(C1-C4)alkanoyl group having two (C1-C4) alkyls at the cycloalkyl moiety, camphorsulfonyl group, carboxy-(C1-C4)alkylcarbamoyl group, tri(C1-C4)alkylsilyl(C1-C4)alkoxycarbonyl(C1-C4)-alkylcarbamoyl group, benzoyl group optionally having one or two nitro groups, benzenesulfonyl group having halogen, or phenyl(C1-C4)alkanoyl group having C1-C4 alkoxy and trihalo(C1-C4)alkyl group. Among these, the most preferable ones are acetyl, carboxypropionyl, menthyloxyacetyl, camphorsulfonyl, benzoyl, nitrobenzoyl, dinitrobenzoyl, iodobenzenesulfonyl and 2-trifluoromethyl-2-methoxy-2-phenylacetyl.
Preferable examples of the xe2x80x9c5- or 6-membered nitrogen, sulfur and/or oxygen containing heterocyclic ringxe2x80x9d include a pyrrolyl group and a tetrahydrofuryl group.
xe2x80x9cA heteroaryl which may be substituted by suitable substituentsxe2x80x9d moiety of the xe2x80x9cheteroaryloxy which may be substituted by suitable substituentsxe2x80x9d may be the ones exemplified for R1 of the compound of the formula of EP-A-532,088, with preference given to 1-hydroxyethylindol-5-yl, the disclosure of which is incorporated herein by reference.
The ticyclic compounds (I) and its pharmaceutically acceptable salt for use in accordance with this invention are well known to have excellent immunosuppressive activity, antimicrobial activity and other pharmacological activities and, as such, be of value for the treatment or prevention of rejection reactions by transplantation of organs or tissues, graft-vs-host diseases, autoimmune diseases, and infectious diseases [EP-A-0184162, EP-A-0323042, EP-A-423714, EP-A-427680, EP-A-465426, EP-A-480623, EP-A-532088, EP-A-532089, EP-A-569337, EP-A-626385, WO89/05303, WO93/05058, WO96/31514, WO91/13889, WO91/19495, WO93/5059, etc.], the disclosures of which are incorporated herein by reference.
Particularly, the compounds which are designated as FR900506 (=FK506), FR900520 (ascomycin), FR900523, and FR900525 are products produced by microorganisms of the genus Streptomyces, such as Streptomyces tsukubaensis No. 9993 [deposited with National Institute of Bioscience and Human Technology Agency of Industrial Science and Technology (formerly Fermentation Research Institute Agency of Industrial Science and Technology), at 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki, Japan, date of deposit Oct. 5, 1984, accession number FERM BP-927] or Streptomyces hygroscopicus subsp. yakushimaensis No. 7238 [deposited with National Institute of Bioscience and Human Technology Agency of Industrial Science and Technology (formerly Fermentation Research Institute Agency of Industrial Science and Technology), at 1-3, Higashi 1-chome, Tsukuba-shi, Ibaraki, Japan, date of deposit Jan. 12, 1985, accession number FERM BP-928] [EP-A-0184162]. The FK506 (general name: tacrolimus) of the following chemical formula, in particular, is a representative compound. 
Chemical name: 17-allyl-1,14-dihydroxy-12-[2-(4-hydroxy-3-methoxycyclohexyl)-1-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9]octacos-18-ene-2,3,10,16-tetraone
The preferred examples of the tricyclic compounds (I) are the ones, wherein each of adjacent pairs of R3 and R4 or R5 and R6 independently form another bond formed between the carbon atoms to which they are attached;
each of R8 and R23 is independently a hydrogen atom;
R9 is a hydroxy group;
R10 is a methyl group, an ethyl group, a propyl group or an allyl group;
X is (a hydrogen atom and a hydrogen atom) or an oxo group;
Y is an oxo group;
each of R14, R15, R16, R17, R18, R19, and R22 is a methyl group;
R24 is a 3-R20-4-R21-cyclohexyl group,
xe2x80x83in which
R20 is hydroxy, an alkoxy group, an oxo group, or a xe2x80x94OCH2OCH2CH2OCH3 group, and
R21 is hydroxy, xe2x80x94OCN, an alkoxy group, a heteroaryloxy which may be substituted by suitable substituents, a xe2x80x94OCH2OCH2CH2OCH3 group, a protected hydroxy group, chloro, bromo, iodo, aminooxalyloxy, an azido group, p-tolyloxythiocarbonyloxy, or R25R26CHCOOxe2x80x94,
xe2x80x83in which
R25 is optionally protected hydroxy or protected amino, and
R26 is hydrogen or methyl, or
R20 and R21 together form an oxygen atom in an epoxide ring; and
n is an integer of 1 or 2.
The most preferable tricyclic compounds (I) is, in addition to FK506, ascomycin derivatives such as halogenated-ascomycin (e.g., 33-epi-chloro-33-desoxyascomycin), which is disclosed in EP 427,680, example 66a.
As the other preferable example of the macrolides as immunosuppressants, rapamycin [THE MERCK INDEX (12th edition), No. 8288] and its derivatives can be exemplified. Preferred example of the derivatives is an O-substituted derivative in which the hydroxy in position 40 of formula A illustrated at page 1 of WO 95/16691, incorporated herein by reference, is replaced by xe2x80x94OR1 in which R1 is hydroxyalkyl, hydroalkoxyalkyl, acylaminoalkyl and aminoalkyl; for example 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin and 40-O-2-acetaminoethyl)-rapamycin. These O-substituted derivatives may be produced by reacting rapamycin (or dihydro or deoxo-rapamycin) with an organic radical attached to a leaving group (for example RX where R is the organic radical which is desired as the O-substituent, such as an alkyl, allyl, or benzyl moiety, and X is a leaving group such as CCl3C(NH)O or CF3SO3) under suitable reaction conditions. The conditions may be acidic or neutral conditions, for example in the presence of an acid like trifluoromethanesulfonic acid, camphorsulfonic acid, p-toluenesulfonic acid or their respective pyridinium or substituted pyridinium salts when X is CCl3C(NH)O or in the presence of a base like pyridine, a substituted pyridine, diisopropylethylamine or pentamethylpiperidine when X is CF3SO3. The most preferable one is 40-O-(2-hydroxy)ethyl rapamycin, which is disclosed in WO94/09010, the disclosure of which is incorporated herein by reference.
The tricyclic compounds (I), and rapamycin and its derivatives, have a similar basic structure, i.e., tricyclic macrolide structure, and at least one of the similar biological properties (for example, immunosupressive activity).
The tricyclic compounds (I), and rapamycin and its derivatives, may be in a form of its salt, which includes conventional non-toxic and pharmaceutically acceptable salt such as the salt with inorganic or organic bases, specifically, an alkali metal salt such as sodium salt and potassium salt, an alkali earth metal salt such as calcium salt and magnesium salt, an ammonium salt and an amine salt such as triethylamine salt and N-benzyl-N-methylamine salt.
With respect to the macrolide compound used in the present invention, it is to be understood that there may be conformers and one or more stereoisomers such as optical and geometrical isomers due to asymmetric carbon atom(s) or double bond(s), and such conformers and isomers are also included within the scope of macrolide compound in the present invention. And further, the macrolide compounds can be in the form of a solvate, which is included within the scope of the present invention. The solvate preferably include a hydrate and an ethanolate.
The dissolution/absorption promoter for use in this invention is not particularly restricted provided that it is capable of dissolving macrolide compound, such as tricyclic compound (I) or its pharmaceutically acceptable salt, therein and/or promoting its percutaneous absorption. For example, the following monohydric alcohol fatty acid esters, dibasic acid diesters and lower alkylene carbonates can be used with advantage.
Monohydric alcohol fatty acid esters (isopropyl myristate, ethyl myristate, butyl myristate, isocetyl myristate, octyldodecyl myristate, isopropyl palmitate, isostearyl palmitate, isopropyl isostearate, isocetyl isostearate, butyl stearate, isocetyl stearate, cetyl isooctanotate, ethyl linoleate, isopropyl linoleate, hexyl laurate, ethyl oleate, decyl oleate, oleyl oleate, octyldodecyl myristate, hexyldecyl dimethyloctanoate, octyldodecyl neodecanotate, etc.).
Dibasic acid diesters
(diisopropyl adipate, dimethyl adipate, diethyl adipate, diisopropyl adipate, diethyl sebacate, diisopropyl sebacate, dipropyl sebacate, diethyl phthalate, diethyl pimelate, etc.)
Lower alkylene carbonates
(propylene carbonate, ethylene carbonate, etc.)
In this invention, the dissolution/absorption promoters listed above can be used each independently or in a suitable combination.
Particularly, diethyl sebacate is the most preferable dissolution/absorption promoter in case of considering stability and/or solubility of the active ingredient, and/or smell, color and touch of the composition.
The amount of said dissolution/absorption promoter in the composition is not particularly restricted but should be large enough to dissolve the macrolide compound and/or promote its percutaneous absorption. For example, its amount is preferably 0.1xcx9c50% (w/w), more preferably 0.5xcx9c30% (w/w), still more preferably 1xcx9c20% (w/w).
The pharmaceutical base for use in this invention is not particularly restricted provided that it is compatible with the other ingredients in the composition and even capable of dissolving the thickener. Particularly, hydrophilic bases capable of dissolving both the macrolide compound and the said thickener are preferred. As such, hydrophilic glycols such as lower alkanediols, e.g. ethylene glycol, propylene glycol, and butylene glycol, are particularly preferred. The amount of the pharmaceutical base in the composition of this invention can be judiciously selected according to its need. Further, it is possible to control the percutaneous absorption of the macrolide compound, by mixing a suitable amount of hydrophilic polymers such as polyethylene glycol with the pharmaceutical base.
The compatibilizing agent for optional use in this invention is a substance which improves the compatibility of the dissolution/absorption promoter with the pharmaceutical base and, as such, includes but is not limited to the following.
Alcohols
(isopropyl alcohol, ethanol, oleyl alcohol, cetanol, stearyl alcohol, 2-octyldodecanol, etc.)
Diethylene glycol mono(lower)alkyl ethers
(diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, etc.)
The most preferred of all are diethylene glycol mono(lower)alkyl ethers, among which diethylene glycol monoethyl ether is particularly preferred. And in case that diethylene glycol monoethyl ether is used, good cutaneous retention of the macrolide compound can be expected. The formulating amount of said compatibilizing agent is not particularly restricted provided that it is added in a sufficient amount to improve the compatibility of the dissolution/absorption promoter with the pharmaceutical base and, as such, may for example be 1xcx9c30% (w/w), more preferably 2xcx9c20% (w/w), most preferably 5xcx9c15% (w/w).
The thickener which is used optionally in this invention is not particularly restricted provided that it is pharmaceutically acceptable and capable of imparting viscosity to the pharmaceutical base, thus including the following organic and inorganic water-soluble macromolecular substances, among others.
(1) Organic Substances
Native polymersxe2x80x94gum Arabic, gum guar, carrageenan, gum tragacanth, pectin, starch, gum xanthan, gelatin, casein, dextrin, cellulose
Semisynthetic polymersxe2x80x94cellulose polymer (methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose sodium, carboxymethylcellulose calcium, etc.), carboxymethylstarch, sodium alginate, propylene glycol alginate
Synthetic polymersxe2x80x94carboxyvinyl polymer (Carbopol), polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, poly(vinyl methyl ether), sodium polyacrylate
(2) Inorganic Substances
Bentonite, synthetic magnesium silicate, magnesium aluminosilicate, silicon dioxide, etc.
The pharmaceutical composition of this invention preferably contains a thickener and the amount of the thickener in the pharmaceutical composition can be judiciously selected according to the objective viscosity of the pharmaceutical composition. For example, the thickener is used in a proportion of preferably. 0.1xcx9c10% (w/w), more preferably 0.5xcx9c5%(w/w). Among the specific examples given above, cellulose polymer such as hydroxy-propylcellulose, carboxyvinyl polymer are more preferable, and it is possible to change the touch of the pharmaceutical composition by changing them.
In addition to the above ingredients, the pharmaceutical composition of this invention may contain the conventional excipient (e.g. lactose, sucrose, starch, mannitol, etc.), stabilizer [antioxidant (e.g. ascorbyl palmitate, tocopherol, etc.)], coloring agent, sweetener, perfume, diluent and preservative, as well as other medicinally active substances. Particularly, the stability of the present pharmaceutical composition can be improved if 0.01-1% (w/w), more preferably 0.05-0.1% (w/w) amount of ascorbyl palmitate is used as the stabilizer.
The pharmaceutical composition of this invention can be used by applying it to the affected site, particularly the skin lesion, once to 4 times daily.
The proper amount of said macrolide compounds in the pharmaceutical composition is dependent on its particular species used, the patient""s age, the type of disease and its severity, and other factors. Typically, the recommended amount relative to the total composition is 0.001xcx9c20% (w/w), more preferably 0.01xcx9c10% (w/w), most preferably 0.03xcx9c3% (w/w). The composition may further contain one or more other drugs which are indicated in diseases of the skin.
Meanwhile, the pharmaceutical composition of this invention can be produced in the same manner as described in the following examples.